70 FOREST TREES OF THE PACIFIC SLOPE. 



long, narrow crowns with more or less weeping branches. Middle-aged and old 

 trunks have reddish cinnamon-brown bark, extremely thick (3 to 6 inches), 

 deeply furrowed near the base of the tree, where the ridges are strikingly 

 massive ; 20 or more feet above, it is much thinner and less deeply furrowed. 

 The exceedingly thick bark of old and of half-grown trees is a most important 

 protection against fire. Very many large trees bear evidence of having passed 

 through a number of destructive forest fires without damage to their vitality. 

 The bark of young trees and branches is thin, scaly, and dark or grayish brown. 

 The color of the foliage, a pale yellowish green, becoming a bright lemon-yellow 

 in late fall, distinguishes the trees from their associates. The leaves, flatly 

 triangular and distinctly ridged or keeled on their inner face, are from about 

 1 inch to nearly 2 inches in length. In cross-section they show a single flbro- 

 vascular bundle in the center and no resin ducts. The number of leaves in a 

 cluster, ranging from 14 to about 30, can not be depended upon as a distinctive 

 character. The cones (fig. 26) mature in one season and are ripe early in 

 August. They open soon afterwards and shed their seeds {fig. 26, a), whicb 

 are light chestnut brown. By the end of October or November the cones have 

 fallen from the trees. Cones vary from about 1 to li inches in length ; their 

 foot-stalks are very short. Cone scales usually with a dense coating of delicate 

 whitish woolly hairs on the outside, below their centers. Seed-leaves, as a 

 rule, 6. Wood, clear reddish brown, heavy, and fine-grained; commercially 

 valuable. It is very durable in an unprotected state, differing greatly in this 

 respect from wood of the eastern larch. 



Longevity. — Long-lived, attaining an age ordinarily of from 300 to 500 years, 

 while the largest trees are probably from 600 to 700 years old. Trees from 16 

 to 20 inches in diameter are from 250 to 300 years old. Further records of its 

 age limits are required. 



RANGE. 



High valleys and mountain slopes of southeastern British Columbia, northwestern 

 Montana, northern Idaho, Washington, and southward to Oregon. 



Washington. — Mountains of northeastern part, Blue Mountains, and southern part on 

 east side of Cascades. Not detected north of Omak Creek (eastern tributary Okanogan 

 River in north central Oregon, latitude 48° 16'), nor in Cascades north of head of 

 Teshastin Creek (tributary Wenache River, latitude 47° 30'). Mount Rainier National 

 Forest, 2,200 to 5,600 feet on divide between Notches and American rivers : also on upper 

 Natches, Tieton, upper Yakima, Atanum, Klickitat, and White Salmon watersheds, and 

 on Mount Adams. Colville National Forest, northward from Columbia River to 4,000 

 feet in Kettle Range. General in Washington addition to Priest River National Forest ; 

 Columbia River in latitude 46° to 49°, and on Kamiak Butte, near Pullman (eastern 

 part State). Occasional stands in Blue Mountains of Wenaha National Forest, at 2,700 

 to 6,000 feet. 



Oregon. — Blue and Wallowa mountains, and Cascades southward to head of Squaw 

 Creek (T. 16 S., R. 9 E., lat. 44° 8'). Cascades, mainly on east side, but extending 

 across divide for short distance, along west side, from township 4, south (south of 

 Mount Hood) to head of Clackamas River (T. 6 S.). On north (at 2.000 feet to 4,600 

 feet), east, and south sides of Mount Hood and southward, on east side of Cascades, to 

 Tamarack Mountain (T. 6 S., R. 9 E.) ; here very abundant. Found next on Me- 

 tolius River (T. 12 S., R. 9 E.), southeast sides of Mount Jefferson, thence extend- 

 ing, southward to head of Squaw Creek (T. 16 S., R. 9 E.), the southmost limit now 

 known. In Blue Mountains, on both sides of north and south ranges (included in eastern 

 division of Blue Mountains National Forest), at 5,000 to 6,000 feet; southward to head 

 of John Day River, and westward to township 30 east. Eastward through Wallowa 

 Mountains to Big and Little Sheep Creeks (T. 46 and 47 E., R. 3 and 4 S.) nearly to the 

 Idaho line. 



The detailed range of western larch in Montana and Idaho will be dealt with 

 in a later bulletin. 



OCCURRENCE. 



Mountain slopes, preferring north and west exposures — stream bottoms, valleys, and 

 flats ; rare in canyon bottoms and on mountain summits. Exacting in requirements 



